The overall objective of the total project is elucidation of the pathogenic factors in acne vulgaris so that preventive measures and more effective therapy can be formulated. Towards this objective, the following studies are planned: a) Continued investigation of the significance of the decreased linoleic acid levels in skin surface lipids in patients with acne. b) Continued study of lipid metabolism in sebaceous glands of man and other appropriate animal models. c) Improvement of the techniques for measuring sebaceous gland function in vivo. d) Further studies on the effect and mechanism of action of oral retinoids on human sebaceous glands and acne.